As known, keyboards are indispensable input devices for people in the modern societies. Generally, plural keys are installed on a top surface of the keyboard. Via the keyboard, the user can press one or more keys to input a command. However, the key of the conventional keyboard has to be provided with a scissors-type connecting element. Since the scissors-type connecting element occupies a lot of space, the thickness of the conventional keyboard is larger. For solving this drawback, a slim-type keyboard is introduced into the market. The slim-type keyboard is equipped with a cantilever structure in replace of the scissors-type connecting element. Generally, the cantilever structure comprises a connection end and a suspension end. The cantilever structure is disposed under the corresponding key to support the key. That is, the bottom surface of each key is contacted with the connection end and the suspension end.
However, the use of the cantilever structure as the support structure of the key still has some drawbacks. For example, when the key is pressed by the user's finger, the connection end and the suspension end are correspondingly moved downwardly. The traveling distance (i.e., the downwardly movable distance) of the suspension end is certainly larger than the traveling distance of the connection end. Consequently, while a single key is pressed down, the key region near the suspension end and the key region of the connection end provide different tactile feels to the user. Under this circumstance, the user feels the discomfort of operating the keyboard.
Moreover, there is a vacant region between every two adjacent keys of the conventional keyboard. The foreign matters such as dust particles or water drops readily fall down to a circuit board of the keyboard through the vacant region. The dust particles or water drops may result in a poor contact problem of the circuit board or cause damage of the circuit board. Therefore, the conventional keyboard needs to be further improved.